Buildings can magnify winds, causing pedestrian hazards. (Picture courtesy of Graham Hughes/Canadian Press.)
When walking to work in any city, you know that around a certain corner you will be hit with a wind blast. You put your head down and soldier through it. In less than a block, it’s gone. You straighten out your hair.
You have experienced a corner vortex, says Haitham Aboshosha, assistant professor of structural engineering at Ryerson University in Toronto. It happens as wind from two faces of a building meet in a rush and swirl. In other places, you may have effects like channeling—where wind attenuates going down a street—or downwashing—where the winds near the top floors cascade down its walls.
For architects who are creating public spaces, and even developers of waterfront projects or even restaurants who are wondering if plates and napkins will stay on the table, wind effects like these can be a disaster.
Toronto had to put climbing ropes along Front Street to keep citizens from being swept away from wind attenuated by tall buildings. (Picture courtesy of Natalie Nanowski, CBC. See here.)
A number of cities, including Toronto, Boston and London, are asking builders and planners to certify that new buildings will not put their citizens at risk or discomfort. Planners will need to model the wind around their planned buildings. Toronto is demanding all buildings of 12 stories undergo a wind assessment.
Winds from the Atlantic hit a…